寻找子集
Array
(
    [0] => Array
        (
            [cid] => 12
            [cname] => 娱乐
            [ctitle] => 娱乐
            [cdes] => 
            [pid] => 0
            [csort] => 100
            [ckeywords] => 
        )

    [1] => Array
        (
            [cid] => 13
            [cname] => 新闻
            [ctitle] => 新闻
            [cdes] => 新闻
            [pid] => 0
            [csort] => 100
            [ckeywords] => 新闻
        )

    [2] => Array
        (
            [cid] => 14
            [cname] => 军事
            [ctitle] => 军事
            [cdes] => 军事
            [pid] => 0
            [csort] => 100
            [ckeywords] => 军事
        )

    [3] => Array
        (
            [cid] => 15
            [cname] => 小娱乐
            [ctitle] => 小娱乐
            [cdes] => 
            [pid] => 12
            [csort] => 100
            [ckeywords] => 
        )

    [4] => Array
        (
            [cid] => 16
            [cname] => 小军事
            [ctitle] => 小军事
            [cdes] => 小军事
            [pid] => 14
            [csort] => 100
            [ckeywords] => 小军事
        )

    [5] => Array
        (
            [cid] => 17
            [cname] => 小小娱乐
            [ctitle] => 小小娱乐
            [cdes] => 
            [pid] => 15
            [csort] => 100
            [ckeywords] => 
        )

)